程序分为编码端和解码端,两端通过tcp socket通信,编码端一边编码一边将编码后的数据发送给解码端,解码端一边接收数据一边将解码得到的帧显示出来。
代码中的编码端编码的是实时屏幕截图。代码调用了Qt SDK。
#ifndef MAPTHREAD_H #define MAPTHREAD_H #include <QThread> #include <QTcpSocket> #include <QTimer> #include <QColor> #include <QImage> #include <QPixmap> #include <QTime> #include <QDateTime> #include <stdio.h> struct AVFrame; struct AVPacket; struct AVCodec; struct AVCodecContext; class MapThread : public QThread { Q_OBJECT private: #ifdef DEBUG FILE* log; QTime* time; QDateTime dt; #endif AVFrame *frame; AVPacket* pkt; AVCodec *codec; AVCodecContext *c; int i, ret, x, y, got_output; int dest_width; //客户端指定的宽度 int dest_height; //客户端指定的高度 int send_width; //发送图像的宽度 int send_height; //发送图像的高度 int scaleby; //缩放是依据目的图像的高度还是宽度 uchar* sent_img_buf; //buffer of the image that have been sent uchar* curt_img_buf; //buffer of the current image uchar* send_data_buf; uchar cmd_buf[4]; int cmd_buf_fill; bool started; bool inited; int interval; //帧间时间间隔 QTcpSocket* mapSocket; QTimer* timer; public: MapThread(QTcpSocket* socket, QObject *parent = 0); ~MapThread(); const static int SCALE_BY_WIDTH = 1; const static int SCALE_BY_HEIGHT = 2; void setSendInterval(int i); signals: public slots: void sendFrame(); void newData(); void newCommand(); void quit(); protected: void run(); }; #endif // MAPTHREAD_H
void MapThread::sendFrame() { if(!started) return; if(!inited) { avcodec_register_all(); c= NULL; pkt = new AVPacket; i = 0; #ifdef DEBUG fprintf(log, "Encode video file %s\n", "test.mpg"); fflush(log); #endif /* find the mpeg1 video encoder */ codec = avcodec_find_encoder(AV_CODEC_ID_MPEG1VIDEO); if (codec == 0) { #ifdef DEBUG fprintf(log, "Codec not found\n"); fflush(log); #endif exit(1); } c = avcodec_alloc_context3(codec); if (!c) { #ifdef DEBUG fprintf(log, "Could not allocate video codec context\n"); fflush(log); #endif exit(1); } //c->bit_rate = 400000; c->width = dest_width; c->height = dest_height; c->time_base = (AVRational){1,25}; c->gop_size = 100; c->max_b_frames = 0; c->delay = 0; c->pix_fmt = AV_PIX_FMT_YUV420P; //av_opt_set(c->priv_data, "preset", "slow", 0); av_opt_set(c->priv_data, "preset", "superfast", 0); av_opt_set(c->priv_data, "tune", "zerolatency", 0); int re = avcodec_open2(c, codec, NULL); av_opt_set(c->priv_data, "tune", "zerolatency", 0); if (re < 0) { #ifdef DEBUG fprintf(log, "Could not open codec:%d\n", re); fflush(log); #endif exit(1); } frame = av_frame_alloc(); if (!frame) { #ifdef DEBUG fprintf(log, "Could not allocate video frame\n"); fflush(log); #endif exit(1); } frame->format = c->pix_fmt; frame->width = c->width; frame->height = c->height; ret = av_image_alloc(frame->data, frame->linesize, c->width, c->height, c->pix_fmt, 32); if (ret < 0) { #ifdef DEBUG fprintf(log, "Could not allocate raw picture buffer\n"); fflush(log); #endif exit(1); } inited = true; } if(mapSocket == 0) { #ifdef DEBUG qDebug()<<"null socket"<<endl; #endif return; } else if(mapSocket->isOpen() == false) { return; } else if(mapSocket->isWritable() == false) { return; } #ifdef DEBUG fprintf(log, "start cap:%d\n", QDateTime::currentDateTime().msecsTo(dt)); #endif QImage image = Interface::grapScreen().toImage(); image = image.scaled(QSize(dest_width, dest_height)); #ifdef DEBUG fprintf(log, "end cap:%d\n", QDateTime::currentDateTime().msecsTo(dt)); //fprintf(log, "cap:%d\n", time->elapsed()); fflush(log); #endif av_init_packet(pkt); pkt->data = NULL; // packet data will be allocated by the encoder pkt->size = 1000000; for (int h = 0; h < c->height; h++) { for (int w = 0; w < c->width; w++) { QRgb rgb = image.pixel(w, h); int r = qRed(rgb); int g = qGreen(rgb); int b = qBlue(rgb); int dy = ((66*r + 129*g + 25*b) >> 8) + 16; int du = ((-38*r + -74*g + 112*b) >> 8) + 128; int dv = ((112*r + -94*g + -18*b) >> 8) + 128; uchar yy = (uchar)dy; uchar uu = (uchar)du; uchar vv = (uchar)dv; frame->data[0][h * frame->linesize[0] + w] = yy; if(h % 2 == 0 && w % 2 == 0) { frame->data[1][h/2 * (frame->linesize[1]) + w/2] = uu; frame->data[2][h/2 * (frame->linesize[2]) + w/2] = vv; } } } frame->pts = i; ret = avcodec_encode_video2(c, pkt, frame, &got_output); if (ret < 0) { #ifdef DEBUG fprintf(log, "Error encoding frame\n"); fflush(log); #endif exit(1); } if (got_output) { #ifdef DEBUG fprintf(log, "start send:%d\n", QDateTime::currentDateTime().msecsTo(dt)); #endif int ss = pkt->size; #ifdef DEBUG qDebug()<<"ss:"<<ss; fprintf(log, "size:%d\n", ss); #endif writeAndBlock(mapSocket, pkt->data, ss); mapSocket->flush(); #ifdef DEBUG fprintf(log, "end send:%d\n", QDateTime::currentDateTime().msecsTo(dt)); #endif av_free_packet(pkt); } i ++; }
#ifndef MAPTHREAD_H #define MAPTHREAD_H #include <QThread> #include <QTcpSocket> #include <QDebug> #include <QImage> #include <QTime> #include "version.h" struct AVFrame; struct AVPacket; struct AVCodec; struct AVCodecContext; #define INBUF_SIZE 4096000 #define AUDIO_INBUF_SIZE 20480 #define AUDIO_REFILL_THRESH 4096 #define QIMAGE_BUFFER_SIZE 12000000 class MapThread : public QThread { Q_OBJECT private: QTime* time; int newF; uchar* img_buf; QTcpSocket* mapSocket; QString address; int port; bool socketConnected; int request_width; int request_height; uchar* recv_buf; uchar* frame_buf; int frame_buf_fill; int frame_bytes; uchar cmd_buf[8]; int cmd_buf_fill; bool cmd_got; bool frame_size_setted; bool cmd_parsed; int subX; int subY; int subWidth; int subHeight; int subSize; int subFill; bool inited; AVFrame *frame; AVPacket* pkt; AVCodec *codec; AVCodecContext *c; int i, ret, x, y, got_output; //QImage* image; uint8_t* inbuf; #ifdef DEBUG FILE* log; int readlen; #endif int decode_write_frame(AVCodecContext *avctx, AVFrame *frame, AVPacket *pkt); public: int received_frame_width; int received_frame_height; QImage* image; MapThread(QString add, int p, int w, int h, QObject *parent = 0); void sendRequestSize(int width, int height); void getSubWindow(); void parseCommand(); void updateFrame(); signals: void frameGot(QImage*); void frameSizeChanged(int, int); public slots: void newData(); void hostConnected(); protected: void run(); }; #endif // MAPTHREAD_H
int MapThread::decode_write_frame(AVCodecContext *avctx, AVFrame *frame, AVPacket *pkt) { int len, got_frame; len = avcodec_decode_video2(avctx, frame, &got_frame, pkt); if (got_frame) { #ifdef DEBUG fprintf(tlog, "get frame:%d\n", QDateTime::currentDateTime().msecsTo(dt)); //fprintf(tlog, "got frame:%d\n", ttime->elapsed()); #endif if(image == 0) image = new QImage(img_buf, avctx->width, avctx->height, QImage::Format_RGB888); received_frame_width = avctx->width; received_frame_height = avctx->height; for(int h = 0; h < avctx->height; h++) { for(int w = 0; w < avctx->width; w ++) { int hh = h >> 1; int ww = w >> 1; int Y = frame->data[0][h * frame->linesize[0] + w]; int U = frame->data[1][hh * (frame->linesize[1]) + ww]; int V = frame->data[2][hh * (frame->linesize[2]) + ww]; int C = Y - 16; int D = U - 128; int E = V - 128; int r = 298 * C + 409 * E + 128; int g = 298 * C - 100 * D - 208 * E + 128; int b = 298 * C + 516 * D + 128; r = qBound(0, r >> 8, 255); g = qBound(0, g >> 8, 255); b = qBound(0, b >> 8, 255); QRgb rgb = qRgb(r, g, b); image->setPixel(QPoint(w, h), rgb); } } #ifdef DEBUG fprintf(tlog, "emit frame:%d\n", QDateTime::currentDateTime().msecsTo(dt)); //fprintf(tlog, "emit frame:%d\n", ttime->elapsed()); #endif emit frameGot(image); } if (pkt->data) { pkt->size -= len; pkt->data += len; } return 0; }
void MapThread::newData() { if(!inited) { avcodec_register_all(); pkt = new AVPacket; av_init_packet(pkt); memset(inbuf + INBUF_SIZE, 0, FF_INPUT_BUFFER_PADDING_SIZE); codec = avcodec_find_decoder(AV_CODEC_ID_MPEG1VIDEO); if (!codec) { #ifdef DEBUG fprintf(log, "Codec not found\n"); fflush(log); #endif exit(1); } c = avcodec_alloc_context3(codec); if (!c) { #ifdef DEBUG fprintf(log, "Could not allocate video codec context\n"); fflush(log); #endif exit(1); } av_opt_set(c->priv_data, "preset", "superfast", 0); av_opt_set(c->priv_data, "tune", "zerolatency", 0); c->delay = 0; if(codec->capabilities&CODEC_CAP_TRUNCATED) c->flags|= CODEC_FLAG_TRUNCATED; if (avcodec_open2(c, codec, NULL) < 0) { #ifdef DEBUG fprintf(log, "Could not open codec\n"); fflush(log); #endif exit(1); } frame = av_frame_alloc(); if (!frame) { #ifdef DEBUG fprintf(log, "Could not allocate video frame\n"); fflush(log); #endif exit(1); } inited = true; } while(true) { int nread = mapSocket->read((char*)inbuf, INBUF_SIZE); #ifdef DEBUG readlen += nread; fprintf(tlog, "recv time:%d\n", QDateTime::currentDateTime().msecsTo(dt)); fprintf(tlog, "recv all:%d\n", readlen); fflush(tlog); #endif if(nread <= 0) break; av_init_packet(pkt); pkt->size = nread; pkt->data = inbuf; while (pkt->size > 0) { if (decode_write_frame(c, frame, pkt) < 0) exit(1); } av_free_packet(pkt); } }
ffmpeg实时编码解码部分代码,布布扣,bubuko.com
原文:http://blog.csdn.net/tobacco5648/article/details/27872431